A secondary battery, which is easily applied to various product groups and has electrical characteristics such as high energy density, is universally applied not only for a portable device but also for an electric vehicle (EV) or a hybrid electric vehicles (HEV), an energy storage system or the like, which is driven by an electric driving source. The secondary battery is attracting attention as a new environment-friendly energy source for improving energy efficiency since it gives a primary advantage of reducing the use of fossil fuels and also does not generate by-products by the use of energy at all.
Secondary batteries widely used at the preset include lithium ion batteries, lithium polymer batteries, nickel cadmium batteries, nickel hydrogen batteries, nickel zinc batteries and the like. An operating voltage of the unit secondary battery cell, namely a unit battery cell, is about 2.5V to 4.2V. Therefore, if a higher output voltage is required, a plurality of battery cells may be connected in series to configure a battery pack. In addition, depending on the charge/discharge capacity required for the battery pack, a plurality of battery cells may be connected in parallel to configure a battery pack. Thus, the number of battery cells included in the battery pack may be variously set according to the required output voltage or the demanded charge/discharge capacity.
Meanwhile, when a plurality of battery cells are connected in series or in parallel to configure a battery pack, it is common to configure a battery module composed of at least one battery cell first, and then configure a battery pack by adding other components to a battery module assembly including at least one battery module.
The battery pack mounted to a vehicle such as an electric vehicle includes a service plug that may cut off the electric connection of the battery pack in order to prevent an electric shock or the like of a worker when the worker inspects or manages the battery pack.
The service plug is also called a safety plug or a manual service disconnect (MSD), and is mounted to the battery pack as a component for electrically connecting the battery module assembly in the battery pack or for cutting off the electric connection of the battery module assembly. When inspecting or managing the battery pack, a worker or the like firstly manipulates the service plug to cut off the electric connection inside the battery pack and then inspects or manages the battery pack, in order to prevent electric shock or the like.
A conventional battery pack includes a plurality of cables having a predetermined length and electrical components in a pack case for the electric connection of the service plug and the battery module assembly. In addition, the conventional battery pack additionally includes separate fixing parts for fixing the plurality of cables and the electrical components in the pack case.
However, the conventional battery pack needs a complicated assembling process due to the plurality of cables, the electric components and the fixing parts for mounting the service plug, which increases the manufacturing cost of the battery pack and thus lowers the price competitiveness.
In addition, the conventional battery pack needs an additional space in the pack case in order to mount these components, which however deteriorates the space efficiency inside the pack case and increases the size of the battery pack.
Moreover, in the conventional battery pack, the energy density of the battery pack is lowered as much as the additional space with the same size, and thus the capacity and output of the battery pack are reduced with the same size.
Therefore, it is required to find a way to provide a battery pack and a vehicle containing the battery pack which may improve the efficiency of the assembling process, secure the price competitiveness, and improve the space efficiency inside the pack case, when the service plug is installed to the battery pack.